Airbus backs overhaul of pitot icing certification standards

New standards for pitot probes are expected to emerge from a working group being founded in the wake of June's fatal loss of an Air FranceAirbus A330 over the south Atlantic.

Airbus is backing creation of the working group, which is set to begin its activities in the first quarter of 2010, after criticising a proposed revision of certification standards as lacking sufficient rigour.

Investigation of the crash of Air France flight AF447 on 1 June - the latest update to which is due this week - has generated concerns over the performance of pitot tubes under icing conditions.

Pitot tube certification is based on requirements laid out in European technical standard order ETSO C16.

While the European Aviation Safety Agency says it is not "presuming on the potential contribution" of pitot icing to the AF447 accident, it opened a consultation in August on revising ETSO C16 - which was based on decades-old criteria - to align it with the US FAA's more modern standard TSO C16a.

But Airbus, in its response to the EASA consultation, has expressed "significant concerns" about the adoption of the updated requirements.

It claims that the icing conditions laid out in the US standard are "not sufficiently conservative" and that icing test requirements are lower than the airframer's own.

Airbus says the standard does not require probes to be tested in ice-crystal or mixed-phase icing, despite their sensitivity to these conditions.

"Such an omission is contrary to the objective of setting a minimum level of performance, particularly as most aircraft fly in such conditions," it says, adding that probes designed and tested only in liquid icing could "require a significant redesign" to meet the stricter criteria.

Airbus also believes that the update should also take installation effects into account, and that probes should be tested at angles of attack up to 15° at least.

It recommends that EASA should dispense with the update in favour of developing new icing requirements through the proposed working group.

EASA states that the update to ETSO C16 is a "first step" that "has to be done" in the interim, but adds: "In the future this ETSO will be upgraded using the outcome of the working group, which will be a new international standard for pitot probes."